Many different applications are possible for plug connectors of this type. One application, which is in the center of interest in the present example, is the assembly and installation of electrically operated components and structural groups, electric circuits, printed circuit boards, or like elements, in automotive vehicle electronics. This field especially focuses on reliability, mechanical and electrical loading capacity, on the one hand, and favorable manufacturing and assembling costs, on the other hand. Another requirement in vehicles and vehicle components involves extensive protection against, or insensitivity to, humidity and contaminants.
Generally, the electrically operated or electrically connected components in an automotive vehicle are connected by way of cables and plug connectors, i.e., plugs and receiving bushes, and like elements. Frequently, costly manufacturing and assembling techniques are used to achieve sufficient sealing against moisture and contaminants, which is of critical importance for the reliability and long service life of the systems. In addition, it is required in the majority of cases that detachment and reestablishment of the connection for maintenance, error detection purposes and similar operations be possible at least several times.
An object of the present invention is to provide a plug connector which is appropriate for such applications, which can be detached and recoupled at least several times, which withstands moisture and contaminants, and which is reliable and adapted to be stressed mechanically and electrically. Another objective of the plug connector is to minimize efforts in manufacture and assembly.
The connector of the present invention has a receiving and guiding bush which accommodates the connecting wire and ends into an extension provided for being filled with a permanently elastic sticky sealing compound and used as a reservoir for the sealing compound, and includes a retaining element into which the wire tip, when inserted into the bush, penetrates through a previously closed foil or a thin wall of any acceptable material.
In this way, a small number of simple and inexpensive components may be used to configure the plug connector, permitting quick asssembly and effective sealing of the point of transition in relation to humidity and contaminants. When the connecting wire is detached and withdrawn from the bush, the point of transition, or the site where the wire passes through, is closed and sealed by the permanently elastic sticky sealing compound. Thus, the point of connection remains sealed until the connecting wire is plugged in again.
In a favorable embodiment of the present invention, the retaining element has the shape of a plug clamp, a soldering bush, or a like element which establishes the electrical contact between connecting wire and the contact element. An appropriate plug clamp of this type is described in the patent application No. 196 15 706.4 (P 8683) which is not yet published.
The connecting wire is preferably insulated, i.e., with an insulating casing which encompasses the metal wire, and extends through the correspondingly dimensioned bush, the extension and the pierceable foil up to the retaining element in which the insulated tip of the wire is inserted. At the transition to the extension, the bush may be provided with a `stripping funnel` or a like device.
The plug connector according to the present invention is especially appropriate for connecting a device to a printed circuit board which is mounted on a flat-surface cooling element (generally an aluminum or copper plate), such that the bush is seated on the side of the cooling element and the retaining element on the side of the printed circuit board, and wherein the connecting wire is passed through corresponding apertures in the cooling plate and in the printed circuit board.
Further, the bush may terminate in an extension that is configured as a recess on the exit side of the bush and is filled with the sealing compound through a separate feed opening or a feed channel. However, it is also possible to pour in the sealing compound through the bush into the extension.
It is possible in all of the previous embodiments that upon insertion of the connecting wire into the bush or into the plug connector, the sealing compound which is thereby displaced is taken up by the extension used as a reservoir. When the wire is withdrawn from the bush, at least part of the sealing compound is again drawn into the opening that is released, and closes the orifice.
In a variation of the plug connector of the present invention which is advantageous or deemed at least sufficient in many cases, the receiving and guiding bush is closed by a pierceable diaphragm on the exit side of the plugged-in connecting wire. When the highly fluid sealing compound is poured in, this compound will collect in the area of the diaphragm and in the adjacent extension. When the connecting wire is inserted and punctures the diaphragm, the elastic sealing compound will seal the orifice area.
Further details and advantages of the plug connector of the present invention can be taken from the following description of embodiments making reference to the accompanying drawings.